Finally A Vr Command

Well enough playing around with external files. It's about time to head back to what VrPython was intended for and write a new function. This one in particular allows the user to parallel part of an existing line. This is a good example of how a program evolves (to say it was intelligently designed probably infers too much), because as it started off the user had to digitize the offset distance. Then with the advent of VrArgs in 3.3.? it seemed like a good idea to put in the option to enter an offset as a argument after the user typed parpart. Of course with the opportunity to put in a argument as an offset, it seemed silly to not have a dialog somewhere. The problem was that I didn't want dialog every time, and you already had to Id the line, start point, end point, and offset which was approaching the limits of how much I wanted the user to have to do. Hence the decision that if you got all the way to the point of digitizing the offset and hadn't specified one but hit an "end" or "#" without doing so the program would bring up a dialog to allow typing one in. Well let's take a look

#This has become the standard I use to start each program.
print 'parprt.py ParallelPartial modified 8:23 AM 7/13/2007'
'''
Copyright 2007 Dennis Shimer, M.A.N. Mapping Services Inc.
Vr Mapping copyright Cardinal Systems, LLC
No warranties as to safety or usability expressed or implied.
Free to use, copy, modify, distribute with author credit.

Inserts a line parallel to the identified line.
Allows for picking start and end points of new line, and offset.
If a number is passed it as the first it will be used as an offset.
If the <#> End button is pressed during offset measurement a
dialog will come up prompting for offset.
'''

Ws=PyVrWs()
Line=PyVrLine()
Gui=PyVrGui()
WsNum=Ws.Aws()
# Create all the objects we will use.

while Line.Id() != -1:
# In theory you could partially parallel many lines
# though in reality it doesn't happen much, but will do so
# until the user doesn't Id a line which returns -1.

....Ws.UndoBegin(WsNum,"inspar_part")
# The undo is inside the Id loop so each line paralleled
# could be undone individually.

....Gui.DspMsg0('Dig start of new line')
# Since GetCoord() isn't very customizable as far as buttons
# and messages, we'll display instructions in the message area.

....Stat1,NewX1,NewY1,NewZ1=Gui.GetCoord('Point1')
# And get a coordinate for where the newly paralleled line
# Should begin.

....Gui.DspMsg0('Dig end of new line')
....Stat2,NewX2,NewY2,NewZ2=Gui.GetCoord('Point2')
# And the same on the other end.

....if VrArgs:
........print VrArgs
........Offset=float(VrArgs[0])
# This whole if statement was added later after the introduction
# of VrArgs. If a string (or multiple strings) are placed after
# the script name, they are passed in as a list of strings. So the
# test would fail if VrArgs was empty (nothing passed) and would
# pass to the else statement. If however something was passed,
# convert it to a real number and assign it to the offset. Bonus
# points for anyone who identifies the huge bug I just noticed in
# this 3 line block.

....else:
# In other words if VrArgs is not true (is empty).

........Gui.DspMsg0('Dig offset # End for dialog') ........StatS,SnapX,SnapY,SnapZ=Gui.GetCoord('Offset')
# Same as above, display instructions and read a coordinate
# that represents how far the cursor is from the line.

........Offset=-1.0*(Line.SnapPoint (SnapX, SnapY)[3])
# Use the computed offset. The -1 is just to correct for
# how SnapPoint computes the distance.

........if StatS:
# This comes about if the user hits the end button instead
# of a 1 to cancel the digitize offset.

............PromBox=VrPromBox('Prompt title',20,1)
............PromBox.AddDouble('Enter a real number',.5,2)
............if (PromBox.Display(0) == 0):
................Offset=PromBox.GetDouble(0)
# Just a simple prombox to allow for entering the offset if
# it wasn't passed or computed in any other way.

....Num1=Line.SnapPointAdd (NewX1,NewY1,0.0)
....Num2=Line.SnapPointAdd (NewX2,NewY2,0.0)
# We are adding points to the line object that was identified
# this is ok because later we will Rec() instead of ReRec() which
# will create a new line.

....if Num1>Num2:
........tmp=Num1
........Num1=Num2
........Num2=tmp
# At one point DelPoints didn't work properly if the beginning
# point was higher than the end point (it may not still, but doesn't
# really matter if it is checked and swapped if necessary.

....Line.DelPoints (Num1, Num2, 1)
# Mode 1 in effect deletes points outside begin and end rather
# than between them (which would be mode 0)

....Line.Offset(Offset)
....Line.Rec(WsNum)
....Line.Plot()
# Take that line object, offset it by the distance entered or
# computed, record it as a new entity, plot it and there you go.
# Part of the original line has been stored as a new line parallel
# to it.
....Ws.UndoEnd(WsNum)

Reminder that as with all other scripts, you can either copy and paste what you see here (substituting your prefered indentation for the holding characters "....", or find the original at http://python4vr.googlepages.com